Attachment for cameras



July 21, 1942 R. P. WUERFEL 2,290,264

ATTACHMENT FOR CAMERAS Filed Dec. 5, 1939 2 Sheets-Sheet l ROBERT WUBBEZ,

INVENTOR ATTORNEYS July 21, 1942. R. P. WUERFEL ATTACHMENT FOR CAMERAS Filed Dec. 5, 1939 2 Sheets-Sheet 2 7/ nounun 6 6&1) 64 ROBBQT P WUERFEL INVENTOR WW/ ATTORNEYS Patented July 21, 1942 7 2,290,264

UNITED STATES PATENT OFFICE 2,299,264 s'rrscmmn'r roe CAMERAS Robert Wuerfel, Ann Arbor, Mich, mime:- to .rlnternational Industries, Inc., a corporation of Michigan Application December 5, 1939, Serial No. 307,877

2; Claims.

This invention relates to an attachment for cameras, and more particularly to a device for synchronizing a flash unit with the operation of a camera shutter to facilitate photography in an otherwise unsatisfactory light.

The primary object of this invention is the provision of a flash unit adapted to utilize a conventional electric .bulb which may be utilized a number ocf times rather than 'the single flash at present permitted of a flash bulb.

A secondary object is the provision of means to control an electrolytic condenser to charge the same to permit imparting an overload to a conventional electric bulb to produce a flash therefrom.

Other objects will in part be obvious and in part be pointed out hereinafter.

fhe invention accordingly resides in the combination of elements, arrangements of parts, and

features of construction all as will be more fully pointed out hereinafter and disclosed in the accompanying drawings wherein:

Fig. 1 is a front elevational view of a camera provided with the attachment of the instant invention, and

Fig. 2 is a schematic wiring diagram showing the control circuit therefor.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Having reference now to Fig. 1, there is generally indicated at III a camera of any desired type provided with a shutter II, a lens (not shown), and a shutter operating member [2. Attached to the shutter operating member 82 is a shutter synchronizing switch I3 of a known type provided with a knob l5, which, in'turn, is provided with a brush type switch (not shown), adapted to close a contact between wires 11 and It for a purpose to be hereinafter described. The rotation of knob I5 is controlled .by a cable release i9 having a conventional button 101- operating the same. Thus it will be seen that pressure on button 20 operates shutter H of the camera and simultaneously closes a circuit between wires l1 and I8.

Secured to camera ID in any desired manner, is a photo flash unit provided with a pair of terminals 25 and 21 to which wires I! and i 8 lead respectively through a cable 28. Unit 25 is comprised of a casing containing a socket 3| attached to which is a reflector 32 and in which is placed a conventional electric bulb 33 which may be of any desired capacity, illu'stratively, as 60 watts or 100 watts.

30 contains a switch 35 adapted to be depressed manually from open circuit position to closed circuit position and returned upon release thereof from closed to open circuit position by a spring 34. Likewise, container 30 contains 3 microfarad 450 volt electrolytic condensers tit, El and 38 connected in series, as will be pointed out hereinafter, and a condenser M. A conventional flashlight battery it is also provided as is a double rectifying vibrator type switch 52 and a step up transformer it.

The operation of the mechanism herein-before set out may be best understood by having reference to the wiring diagram shown in Fig. 2.

From light bulb 33, wire ll leads to the high voltage secondary 43a of transformer 63. Wire it; leads to one contact 50 of switch it which is also provided with a second contact kit from which wire 52 leads to terminal 53 of one portion,' l2a, of double vibratory switch :32. Fortion @211 is adapted alternately to engage contacts 54 and 55. From contact 58, wire at leads also to secondary 43a of transformer it. Similarly from contact 55, wire 5? leads to the opposite side of secondary 4312. A wire 58 leads from wire 52 to condensers 36, 37 and 38 and an additional wire 59 leads to the opposite side of said condensers from wire i'i. From the primary 13b of transformer 43 a wire 60 leads to one contact 5| adapted to be engaged by the second portion, 42b, of switch 42. Similarly from the opposite side of primary 43b, 9. wire 52 leads to a corresponding contact 63, likewise adapted to be engaged :by member 421). Similarly from an intermediate point of primary 43b, a wire 54 leads to one side of battery 4| from which a wire 65 leads to one terminal 66 of switch 35, of which the other terminal, 51, is connected by a wire 58 to member 42b.

The operation of the device should now be readily understandable. Closure of switch 35 Casing causes energization of vibratory switch 42 which causes portions 42a and 42b to vibrate respectively between contacts 54 and 55 and contacts SI and 53. The dotted line in Figure 2 illustrates diagrammatically a mechanical connection between switch members 42a and In. This mechanical connection is preferably oscillated by an electromagnetic vibrator of the type usually employed in vibrator rectifier apparatus to cause synchronized movements of switch portions 42a and 42b.

I It ,is to be understood that the vibrator rectifler apparatus embraced by the bracket in Figure 2 may be of any conventional type wherein the low voltage primary of e transformer is reoeotedly interrupted and reversed and the high voltagel secondary is rectified, such on in the usual vibrator rectifiers loyed in entomofbiles ior energizing radio receivers and the type disclosed in United States Letters Patent No. 1,920,150, Timed manual closure of switch 35 establishes a circuit from battery ll, wire 65, contacts 86 end or, wire 68, alternately cone tocts ti and G3, and surly alternately wires to end or, to primary lib thence through wire (it to battery st. in this manner, the charge is built up in pry 38b which is stepped up in secondary tile. The increased charge oi primcry it?) which, it is to be noted, is by the vibretory notion oi member @Zb, translated to direct current, due to the alternate positive end negoiive circuim, estnblished in a known manner, passed a circuit corised-al= ternstely of secondary the, wire 56, contact 54. member 52a, terminsl E18, wire 52, wire it, con= densers 363, 871 end 38, wire 59, wire i'i, back to secondary 33a; end secondary its, wire bl, contact 65, member We, terminal 58, wire 52, wire or, condensers 88, 377 end 38, wire to and wire it; into the condensers 538, Si and 38 where it is built up into is charge of approidmotely 450 volts, m rupon end vorying somewhat with the length of time the switch 3E5 is deiormed. When the condensers it, ill and 38 have achieved their opproxirnste capacity, the manual switch 35 is released and the device is now fully charged and resdy for o erution.

When such operation is desired, push button it is depressed which closes switch it end establishes an overload circuit through bulb 33, such circuit being as follows:

Condensers 3t, 87? end 88, wire 58, switch 113, including contacts ti and to, wire it, the filament of bulb 33,- wire ill, wire it and back to the condenscrs. A wire it leads from wire m; to con= denser so and wire it leads from wire d?! to the opposite side of condenser dd. Thus it will be seen that condenser Gil is connected in parallel with the secondary the of transformer 63 end its sole purpose is to provide o means oi absorbing surges transmitted to the secondnry, in it known manner, to preclude overloading or buming out of the secondary 63a.

This momentary overload creates s brilliant flash in bulb 83 sumcient for any desired photo= graphic necessity in either s dim light or in darkness.

Now from the foregoing it will be seen that there is herein provided s device which eccom plishes all the objects of this invention and others including many advantages of great practical utility.

As many embodiments may be made of this inventive concept and as many modificetions may be made in the embodiment herein shown and described, it is to be understood that all mutter herein set forth or shown in the occompg drawings is to be interpr ted merely as illustrative and not in a limiting so.

What is cl or and tr to be secured by Letters Pat is:

1. in c ere he to shutter and shutter operating moons, n photo phic light attachment ior said camera. cepsble or repeated use and comp on incandescent lump or relatively low ccpaclty, a condenser, c buttery, means to charge said condenser irom said battery to e. relatively high voltage, sold menus comprising s transformer connected to the battery and the con denser ond vibrating menus for interrupting the current from said buttery end rectiiying the voltsse across sold condenser and means including a. switch octuctccl by cold shutter actuating means to discharge solid condenser throuyh sold lamp for momentsrily overloading sold lamp shove its normal capacity and producing 29. brilliant dash.

2. A self contained iisght attachment for use with c comers hcvinc; c shutter, sold attachmerit comprising o batten, n transformer having its pry (0,220. connected to sold battery, a.

condenser connected across the secondary winding oi said trcnsformer, moons for periodically reversing the current in the primary winding, means for rectifying the secondary voltage, a lamp and moons for simultaneously actuating the camera shutter end discharg ng the condenser i. u comers hsving o, shutter, means for actuating sold shutter to make on exposure, a light source, as condenser, as battery, means for charging sold condenser from sold battery comprising s transformer connected to said battery end said condenser, and vibrating means interrupting the current irorn sold buttery and rectifying the current to sold condenser, and means for simultaneously onernting sold shutter and discharging sold condenser through said light source.

5. in c comers hsving o. shutter, a. light source, c condenser, e buttery, means for charging said condenser comprising s step on transformer, having its primary connected to said battery and its secondary connected to said condenser, means for periodically interrupting the primary current and means for rectifying the secondary voltage, actuating means for operating the shutter to make on exposure, and means ior simultaneously discharging said condenser through said light source.

ROBERT P. WUERFEL. 

